Impact of weight change on the prognosis of cancer patients: a multicenter, prospective study.

BACKGROUND & AIMS: Weight loss may increase the risk of death from cancer; however, research findings are mixed, and little is known about the effects of weight gain. We evaluated the association between weight change in the 2 years after diagnosis and the risk of all-cause mortality in Chinese adult patients with cancer. METHODS: This prospective cohort study included 2,795 adults with cancer. The association between weight change and all-cause mortality of cancer patients was explored using Cox proportional hazards model and restricted cubic spline model. Subgroup analysis and interaction terms were used to explore whether weight change was associated with certain variables. Then, 2,067 subjects who did not experience weight gain at the first follow-up visit were used to test the association between all-cause mortality and weight change between baseline and the first follow-up visit and between the first and last follow-up visits. RESULTS: After adjusting for confounding factors, weight loss was linked to a higher risk of all-cause mortality: the hazard ratios for the severe and moderate weight loss groups were 2.03 (95% CI: 1.62-2.55) and 1.40 (95% CI: 1.09-1.80), respectively. When assessed by gender, the overall trend was consistent with that of the general population, but the association between weight loss and poor prognosis was more pronounced in male patients. There was no significant association between weight gain and the risk of all-cause mortality. Regardless of subsequent weight regain, weight maintenance, or weight loss, cancer patients who experienced severe weight loss within two years were associated with an increased risk of mortality. CONCLUSION: Weight loss was linked to an increased risk of all-cause mortality in cancer patients, particularly in males. Regardless of subsequent weight fluctuations, severe weight loss remained associated with an increased risk of all-cause mortality.